Published works have indicated that water movement across human red cell membranes is through hydrophilic pathways. There is evidence which suggest that these aqueous pathways may be assembled from aggregates of integral membrane proteins which span the membrane thickness. We plan to test directly whether the incorporation of band 3 protein or band 3 protein in conjunction with glycophorin isolated from human red cell membrane into liposomes will increase the permeability of these liposomes to water and small nonelectrolytes.